perimeter perimeningitis • perimeterless · · · Info · Definitions · Synonyms · Characters · · perimeter · · Text Latin · · Script 9 · · Length Definitions · · · (noun) the boundary line or the area immediately inside the boundary. Synonyms: margin, border. · · Noun Definition 1 (noun) a line enclosing a plane areas. · · Noun Definition 2 (noun) the size of something as given by the distance around it. Synonyms: circumference. · · Noun Definition 3 Synonyms · · · margin · · Synonym 1 border · · Synonym 2 circumference · · Synonym 3 Characters · · e latin small letter e U+0065 i latin small letter i U+0069 m latin small letter m U+006D p latin small letter p U+0070 r latin small letter r U+0072 t latin small letter t U+0074